Effects of prolonged ingestion of glucose or ethanol on tissue lipid composition and lipid biosynthesis in rat.

The effects on lipid metabolism of long-term feeding of large amounts of ethanol or glucose differed from those that have been reported in short-term experiments. Three groups of male rats were investigated. The first was fed lab chow and 15% (v/v) ethanol ad lib.; the second was pair-fed with the first and given isocaloric amounts of glucose in lieu of ethanol; the third was fed lab chow and water ad lib. All three groups consumed nearly the same number of calories, and about 30% of the calories in the first group were derived from ethanol. Neither glucose nor ethanol added to a nutritionally adequate diet promoted the development of a fatty liver, although both stimulated acetate-(14)C utilization for hepatic lipid synthesis. In all three groups more than 80% of the label in hepatic lipid was found in fatty acids, and the distribution of label amongst the fatty acids of different chain lengths was virtually the same. Ethanol decreased while glucose increased the quantity of lipid in fat depots, and each altered the fatty acid composition of the lipids in adipose tissue, kidney, liver, and hepatic subcellular fractions in a different manner. The most striking of these changes was the relative increase in monounsaturated fatty acids and the decrease in essential fatty acids produced by glucose.